WATER VAPOUR TRANSFER THROUGH MICROPOROUS MEMBRANES AND POLYESTER TEXTILE MATERIALS UNDER SIMULATED ALTITUDE CONDITIONS -COMBINED INFLUENCE OF TEMPERATURE AND PRESSURE -

摘要

The combined influence of temperature and pressure upon water vapour transport in textile materials is investigated to design clothing system for cold environment and high altitude. In the study, a microporous membrane PTFE and several types of PET are selected because of wide usage in sports apparel marketing. The water vapour resistance of the PTFE is independent of both temperature and pressure and remains at about 4 s/m. On the other hands, that of the PET is appreciably influenced by the combination and decreases with the increasing altitude. This difference is discussed in terms of relation between the pore size in the specimen and the mean free path of the water vapour molecules.